Airlock with a pneumatic orifice for the vacuum train system

ABSTRACT

The disclosure describes an airlock with a pneumatic orifice, characterized in that the orifice chamber is located inside the tunnel, together with an inactive expansion element made up of a flexible material consisting of an external torus and an internal membrane, which is activated by compressed air produced by compressors placed in a housing.

The subject of the invention is an airlock with a pneumatic orifice, in the shape of a torus with an internal membrane, activated in order to close the clearance of the tunnel tube of the vacuum train system.

Document WO2016126507 describes the valve and air blockade for high speed transport systems and the methods of using them. Some embodiments of this disclosure focus on a shut-off valve acting to isolate sections of tubular construction under external pressure, vacuum or near vacuum.

In one of the embodiments, at least one tube seal contains an air cushion, which is inflated in the transport path to form an airlock in at least one tube.

In another embodiment, a durable high-pressure bubble (or airbag) can be used as an airbag. The airbag may contain soft polymeric material which is embedded in the tube surface and can be quickly filled with gas when a quick closure, such as an emergency, may be necessary, minimising the change in pressure in the tube.

It can be equipped with an airbag inflation mechanism using an air pump or a pre-charged container. The airbag may include an activatable opening in the tube to allow ambient air to flow into the interior and fill the airbag. The closing valve contains at least one actuator configured to selectively move the closure to and/or from the transport route. The solution includes sealing measures arranged approximately around the circumference of the airbag (e.g. when unfolded).

However, these devices still do not solve the problem of effective use of airbags in case of complex tunnel cross-section geometry (the existing solution is proposed for sealing the circular cross-section, but it does not take into account e.g. the railroad bed or ancillary equipment “disturbing” the circular cross-section of the tube).

In addition, there is a need to create solutions that are more compact than known equipment, as it takes up less space, both folded and unfolded, which may be important for the installation of airlock at tunnel sites with a large number of ancillary equipment, or in underground tunnels where space saving is important in terms of cost.

Airlock with a pneumatic orifice for the vacuum train system, inside the vacuum tunnel housing, is provided with a chamber with a folded pneumatic orifice shaped to fit the geometry of the tunnel and railroad bed, capable of completely closing the clearance of the tube/tunnel at full unfolding. The pneumatic orifice consists of a torus-shaped outer element and an inner membrane made of high-tensile strength material.

The essence of the invention is an airlock with a pneumatic orifice, characterized in that inside the tunnel there is an orifice chamber with an inactive expansion element made up of a flexible material consisting of an external torus and an internal membrane, which is activated by compressed air produced by compressors placed in a housing.

Advantageously, the pneumatic orifice chamber with a folded expansion element is located both at the side of the tube and at the top of the tube.

Advantageously, the airlock is composed of at least one expansion element to form pneumatic elements of the airlock, which work together to close and seal the tunnel clearance.

Advantageously, the airlock with a pneumatic orifice is composed of several pneumatic elements characterized in that the elements of the airlock can be triggered sequentially in order to obtain a proper closure of the tunnel clearance.

Advantageously, the contact between the two elements of the airlock can be closed by friction forces, by means of magnets or by means of adhesive substances.

Advantageously, the airlock with a pneumatic orifice is stabilized against the tube interior surface by friction forces, by means of magnets or stabilizing rings, or by means of adhesive substances, or by means of additional pneumatic elements, which can play a stabilizing role in addition to sealing.

Advantageously, the airlock with pneumatic orifice is activated automatically or manually.

The invention consists in the fact that inside the tunnel there is a pneumatic orifice chamber connected with the housing construction, in which an expanding element filled with compressed air from a container or a set of compressors is placed, which in case of activation causes a quick closure of the tunnel clearance and reduces the risk of the section air lock.

For the correct location of the pneumatic orifice in the tunnel cross-section, it is advantageous to make an inner flange inside the tube, which does not collide with the vehicle clearance gauge. By using a flange it is possible to achieve proper stabilization of the orifice subjected to one-sided pressure of the air column. The support of the expansion element in the tunnel section is guaranteed by the friction forces at the contact between the tube wall and the surface of the torus. The orifice zone between the stabilizing flanges should be roughened in order to increase the coefficient of friction between these elements. However, it is necessary to induce significant overpressure in the torus flange—a pneumatic element so that friction forces block the movement of the element.

Thanks to this solution, it is possible to use an expansion element as an emergency solution, enabling quick closure of the pipe/tunnel clearance in case of pipeline integrity loss or vehicle failure.

In the case of more than one pneumatic element, the pneumatic elements of the airlock work together to form a tight seal of the tunnel clearance.

The roughened surface is the surface with an increased coefficient of friction between the tunnel and the expansion element. In this case, the roughening can be achieved by increasing the roughness of the tunnel surface by grinding with an abrasive with a FEPA grit of P30-P180. The second way to “roughening” the tunnel is to cover the surface of the tunnel section, which is in contact with the surface of the expansion element, with an elastomer e.g. silicone or butyl rubber (IIR) by spraying. Covering the surface with elastomer also increases the coefficient of friction between the tunnel surface and the expansion element and additionally seals the airlock.

The subject of the invention is depicted in the embodiment and shown in the figure on which the FIG. 1 represents a cross-section through a vacuum tunnel with an inactive air orifice, FIG. 2 shows the same vacuum tunnel with an active air orifice, FIG. 3 shows the arrangement of forces acting on the orifice and the place of installation of the holding flange is marked. Special variants of the solution of the invention are shown in FIG. 4, where the possible position of the orifice chamber 5 in the cross-section is shown, and FIG. 5 where the possibility of using a closing orifice consisting of more than one element is shown, FIG. 6 shows the active pneumatic orifice and FIG. 7 shows the operation of the airlock with a pneumatic orifice.

EXAMPLE 1

In tunnel 1, where orifice chamber 5 is installed with a folded expansion element 4, there is a vacuum. Pneumatic orifice 5 is defined as an expansion element with a membrane, which is active (filled with gas) during closing the tunnel clearance in order to isolate a fragment of the tunnel, while expansion element 4 is understood as a properly sewn material, closed in the orifice chamber and waiting to be activated. The pneumatic orifice is designed to choke or completely close the tunnel clearance, i.e. block the flow of gases. The pneumatic orifice chamber 5 is located on the side of the tunnel or at the top of the tunnel. Activation of the orifice by filling it with compressed air from compressor 10 mounted to the orifice chamber 5 housing, results in tight filling of the tunnel section with expansion element 4 of the pneumatic orifice consisting of torus 6 of flexible material and internal membrane 7 of high strength material and strict adjustment to the shape of the railroad bed 3. Expansion element 4 is stabilised and secured against displacement by internal rings integrated in the tunnel structure 8, by the roughness zone of the tunnel surface in the ring zone 8 or/and by magnets 9. The contact between the two parts of the airlock can be closed by frictional forces, by means of magnets or by the use of adhesive substances such as polyisobutylene or similar. The inner membrane 7 is made of at least two layers—a sealing layer and a structural layer. The sealing layer may be made of elastomer based on synthetic rubber or similar (neoprene), while the structural layer is made of e.g. aramid fibres. Expansion element 4 (torus) has a similar structure as the membrane.

Example 2

Example of automatic operation of an airlock with a pneumatic orifice:

The pressure sensors are located along the tunnel at a certain distance (e.g. 200-1000 m). At a certain moment, one of the sensors detects a surge in pressure, which indicates a significant leakage of the tunnel. The information about the leakage is sent via a monitoring system to the two pneumatic locks closest to the pressure sensor. After receiving the information, the pneumatic locks are activated automatically causing the unsealed tunnel element to be cut off.

Example of manual operation of an airlock with a pneumatic orifice:

A vehicle moving in a tube breaks down and passengers need to be evacuated. As a result, it is stopped and the operator decides to operate the airlock with pneumatic orifices adjacent to the vehicle. After the locks have been activated, the pressure in the isolated section is equalized to atmospheric pressure and passengers are evacuated through an appropriate evacuation exit.

The locks of the invention can be used to protect vacuum train tunnels on the route, in station zones and service tunnels, depending on safety requirements and operational needs. 

1. An airlock with pneumatic orifice, characterized in that the orifice chamber is located inside the tunnel, together with an inactive expansion element made up of a flexible material consisting of an external torus and an internal membrane, which is activated by compressed air produced by compressors housed in a housing.
 2. The airlock according to claim 1 characterized in that the orifice chamber together with a folded expansion element is located both on the side of the tube and in its upper part.
 3. The airlock according to claim 1, characterized in that it comprises at least one expansion element forming pneumatic elements of the airlock that cooperate with each other.
 4. The airlock according to claim 4, characterized in that it consists of several expansion elements, which are triggered sequentially.
 5. The airlock according to claim 5, characterized in that the contact between the expansion elements and between the expansion element and the tunnel wall is closed by friction and by means of magnets or by the use of adhesive substances.
 6. The airlock according to claim 1, characterized in that it is stabilized against the inner surface of the tube by friction.
 7. The airlock according to claim 1, characterized in that it is activated automatically.
 8. The airlock according to claim 1, characterized in that it is activated manually.
 9. The airlock according to claim 1, characterized in that it is stabilized against the inner surface of the tube by one or more magnets.
 10. The airlock according to claim 1, characterized in that it is stabilized against the inner surface of the tube by one or more stabilizing rings.
 11. The airlock according to claim 1, characterized in that it is stabilized against the inner surface of the tube by one or more adhesives.
 12. The airlock according to claim 1, characterized in that it is stabilized against the inner surface of the tube by one or more pneumatic elements. 